1. Field of the Invention
The present invention relates to a liquid crystal panel for eliminating static electricity generated during the manufacture of the liquid crystal display, and a method of operating the same. More particularly, the present invention relates to a static electricity prevention type liquid crystal panel and a method of operating the same which allows testing of a driving circuit and a pixel section of a driving circuit integrated TFTLCD (thin film transistor liquid crystal display).
2. Description of Related Art
Generally, when manufacturing an LCD panel, static electricity is generated from the upper and lower glass panels of a liquid crystal display panel. If the generated static electricity is maintained, it makes accurately manufacturing the liquid crystal display difficult.
Techniques are suggested in Japanese laid-open patent publications 58-116573 and 63-220289 for eliminating static electricity generated in the liquid crystal panel during the manufacturing process. Since these techniques are described in detailed in the above mentioned publications, the following description of these techniques is provided to discuss problems arising from manufacturing and operating a liquid crystal display device using the above described techniques.
FIG. 1 shows a perspective view of conductive lines of a conventional liquid crystal display for illustrating the conventional method of preventing static electricity as described in Japanese laid-open patent publication 58-116573.
As shown in FIG. 1, a plurality of signal lines G and a plurality of data lines D cross each other to form a cell array. The signal lines are also known as gate lines G. A short conductor ST commonly connects the gate lines G and data lines D so as to maintain the voltage levels thereon at an equal electric potential and eliminate static electricity.
Later in the manufacturing process, the gate lines G and the data lines D are severed according to the dotted line CL. The cut portions of the gate and the data lines G and D are connected to separately manufactured gate driving and data driving circuits (not shown), respectively, to form the liquid crystal panel.
Recently, in order to form a high resolution liquid crystal display panel, a driving circuit and a cell array have been integrated to simplify the manufacturing process and to enhance the reliability of the liquid crystal display device. However, the above described technique for preventing static electricity is not applicable to such an integrated liquid crystal panel for the following reasons.
As shown in FIG. 1, since all of the conductive lines are connected by the short conductor ST, testing of different driving circuits cannot be performed during the manufacturing process.
FIG. 2 shows another technique for preventing static electricity as described in Japanese laid-open patent publication 63-220289.
As shown in FIG. 2, a reference potential line SL is provided external to the region where the gate and data lines G and D are positioned. The reference potential line SL has a certain electric potential value. The source terminals of NMOS transistors 2 are connected to the reference potential line SL, while the gate and drain terminals of the NMOS transistor 2 are connected to an associated data line D. The source terminals of NMOS transistors 4 are connected to the reference potential line SL, while the gate and drain terminals of the NMOS transistors 4 are connected to an associated gate line G. Therefore, the gate lines G and the data lines D are connected to the reference potential line SL through a terminal element of an NMOS transistor. Through the gate lines G and data lines D, a certain voltage generated due to static electricity is input to the NMOS transistors 2 and 4 so as to minimize malfunctions caused by the static electricity.
In the above method, however, if the turn on voltage level is low for the NMOS transistors 2 and 4, currents from the gate and data lines G and D flow therethrough and cause problems for accurately imputing data to the pixels.